The constitutional amendment figures to be Minnesota’s fiercest political fight of the year. Gay marriage is legal in six states, including Iowa, but it’s not legal in several more.

No state has ever defeated a gay marriage ban when it’s been on the ballot, and 29 states have put it in their constitutions.

Gov. Mark Dayton predicts Minnesota will be the first to change that.

“I think Minnesota is better than that. I think Minnesota is an exceptional state. I think we are a state that understands human beings and has a compassion for people and our uniqueness and our similarites that goes beyond any other state in this nation. We’re going to prove it. We’re going to prove that we are better,” Dayton said.

Minnesotans will be asked to vote on: “Only a union of one man and one woman shall be valid or recognized as a marriage.”

Many young people attended the rally. Some Augsburg College students described gay marriage as the next civil rights bridge Minnesotans will cross.

“Like my sign says: Love is love and it shouldn’t matter what sex you are and who you are with. If you love who you love, you should be able to marry them and you should have the same rights,” one student said.

The gay marriage fight is already shaping up as the fiercest political fight of the year. Gov. Dayton is not the only chief executive urging a “No” vote.

Former Gov. Jesse Ventura sent a video message, apparently from his home in Mexico.

“Do not support changing the constitution to discriminate. That isn’t what Minnesota or our country should be about,” said Ventura.

The sponsors of the gay marriage ban, a group called “Minnesotans for Marriage,” issued a written statement Thursday expressing confidence in the outcome this fall. They say their efforts to persuade Minnesotans are going very well, and that they are ahead in every credible poll.

There’s a much higher standard to amend the constitution. It’s not just a simple majority vote, it takes a super majority of everyone who votes in the election.

Typically it takes about a 60 percent “yes” vote to change the constitution.